Devices to improve flow pattern and heat transfer in heat exchange zones of brick-lined furnaces



Nov. 19, 1957 K. P. H. FREY 2,313,703

DEVICES TO IMPROVE FLOW PATTERN AND HEAT TRANSFER IN HEAT EXCHANGE ZONESOF BRICK-LINED FURNACES Filed Oct. 8, 1951 5 Sheets-Sheet 1 FIG. 4 FIG.5 FIG. 6

INVENTOR 45 KURT PAUL HERMANN FREY BY f UM ATTORNEYS 2,813,708 TRANSFERNov. 19, 1957 K. P. H. FREY DEVICES TO IMPROVE FLOW PATTERN AND HEAT INHEAT EXCHANGE ZONES OF BRICK-LINED FURNACES 5 Sheets-Sheet 2 Filed Oct.8,

FIG" /0 FIG. .9

Y WE mm 3 v W. N M m MM F IR E H l.- m \P 2 T MW 6 IK. F m H H 4 l I l aa I 6 F I! O 1 F 7 ATTORNEYS Nov. 19, 1957 K P H. FREY 2,813,708

DEVICES TO IMPRO VE FLSW PATTERN AND HEAT TRANSFER IN HEAT EXCHANGEZONES OF BRICK-LINED FURNACES Filed Oct. 8, 1951 5 Sheets-Sheet 4 2 2628V NVENTOR 62 KURT PAUL HERMANN REY wm zm, LQL -x 260 260 BY P 259 I 259ATTORNEYS Nov. 19, 1957 K. P. H. FREY 2,813,708

DEVICES TO IMPROVE FLOW PATTERN AND HEAT TRANSFER IN HEAT EXCHANGE ZONESOF BRICK-LINED FURNACES Filed Oct. 8, 1951 5vSheets-Sheet 5 FIG. 26

' INVENTOR" KURT PAUL HERMANN FREY PWL ATTORNEY S United States PatentDEVICES TO IMPROVE FLOW PATTERN AND HEAT TRANSFER IN HEAT EXCHANGE ZONES0F BRICK-LINED FURNACES Kurt 'Paul Hermann Frey, Goggingen, nearAugsburg, Germany Application Dctober. 8, 1951, Serial No..250,362

1 Claim. (Cl. 263-51) In recuperative and also in regenerative heattransmitters or heat exchangers .of refractory brick, in industrialfurnaces of refractory brick such as mufile furnaces,

enameling furnaces, open-hearth furnaces, coke furnaces or similarequipment, heat is transmitted to the-brick by encountered in most, ifnot all, of the conventional furnaces. The conventionalbrick-linedfurnaces and heat exchangers may have good flow patternsunder one set of operating conditions butfrequently this set ofconditions is not that which is observed in actual practice andseparationof the flow with concomitant poor heat transfer and thedevelopment of hot spots occurs in actual practice to materially detractfrom the efificiency of the furnace and heat exchange operation.

In recuperative and regenerative heat exchangers and heattransmittersand in industrial furnaces thereresults, due to a sharp deviation of thereal flow development from the assumed flow development, extremelyirregular heat transitions which at many points are on the one handextremely high and on the other hand at some points almost lacking. Bymeans of forced convection and as a result thereof heat stresses andlocal overheating or insufficient heating of the brick materialfrequentlyresults and the consequence of this, in turn, is loss in theutilization of the thermal properties of the brick, with the-additionaltendency of the brick to crack due touneven heating which introducesfurther hazards to'the safety of operation. The flame length isfrequently impossible to control due to operations whichoccur. in theflow pattern. A further consequence is the greatly re- .duced stabilityof the brick material, the premature dedead-water areas in and aftersudden bends or enlargements in the cross section and the accumulationof'rsla'g deposits atsuchpoints; such deposits or accumulations cause acontinuing weight increase at the affected brick walls or vaults withoverheating and harmfulcontrol spots developed.

The present invention provides devices for the improvement of the flowpattern in the refractorybrick-lined channels of coke furnaces, muiflefurnaces and .the like 2 wherein .the combustion gases and air aresubjected to changes in direction due to the connection of the inletandoutIeLchannels Within .the furnace so as to provide.a,poorl-flowpatternin which there are formed separation .zones .in thecross section ofthe fluid stream, static and.eddy.areas-.immediatelyadjacent themainflow of the gasesand airthroughthe channels, the improvement by the devices of thepresentinvention. comprising providing deflecting rneansat the boundaryof thezone of separa* tion to.deflect..the gases. into thestatic zone, saiddeflectingmeans comprisinga staggered series of curvedvane.gui'di-ngsurfaces, the. curved vanes being eachadisposedon-.the.suction.side of thesubsequent vane, the resultant curvature ofthe series .beinggreater than the curvature dfanysingle vane, the amount.ofoverlap of the values withres-pect to each other beingsufficienttoprovide a :substa-ntialjet directed velocity vector inadirectionsu'b .stant-ially tangential to the resultant-curvature ofvthe series, .the resultant curvature of the series being defined by. thecurve which joins the intersections of the.cords of. the vanes, theangleofjattackof the first vanes beingnegative with respect .to-the.directionof the velocity vectorot the instantgas stream.

An.object.of 'thepresent invention is to overcome the drawbacks .of Lprior known .devices and the invention ,provides deflecting means ..at.the boundary of .thezone of separation in the cross section of thechannels-between the inlet and outlet openings of brick-lined furnaces,heat exchangers and the like .to deflect the gases into the staticzouebetween the zone of separation and the brick-lined channel Wall,said deflecting means comprising a stag- .geredsseries of curved .vaneguidingv surfaces, the curved vanes being each disposedon the=suctionsideofthesubsequent vane, theresultant curvature of the series beinggreater than the curvature of any single vane, the amount of overlapofthe vanes with respect to each other being sufficient to provide asubstantial jet directed velocity vector .in .a 'direction substantiallytangential .tothe resultant .curvatureof the series, .the resultantcurvature of theseries being defined by the curve which joins theintersections of ,thelcordsof the vanes, the angle of. attack ofthefirst vanes being'negative with respect to the .direction of ,thevelocity vector ofthe instant-gas stream. I By means of the invention.pressu-re losses are reduced, whereby in. tur-n the current costs ofoperationeandalso the production costslbecome smaller; forexample, with"the same output the equipments may be givensmaller dimensions,:henceprovidinga better utilization of space .and at the same time morefavorable possibilities .for more efficient dust-removal chambers andslag-deposit chambers in the equipments.

A further .objectof 'the invention is to make it possible ,to controlthe heat transition as toquantity and space by varying the heattransmitted byconvection, and by reducing the heat transmitted byradiation.

Further objects-of the invention will be apparent from the followingdetailed discussion .of preferred embodiments of the invention takentogether with the accompanying drawings, in which:

Figs. 1 to 12are partial views of apparatus embodying "the features ofthe present invention and relating to a streamline principle;

"Figs. 13rto 20are views=sirnilar to' Figs. l-to 12 but embodying aresistance principle; and

'Figs.21*to. 33 are'partial views showing -the use of comb'inationsofmeans in varying devices and equipment.

The: invention locates deflecting means at the boundary -.of the-zoneof. separation for the improvement of *the flow, particularly forthe eliminationoflarge detachments -ofthe.flowaandeforttheimprovement ofthe velocity disntribution of the flow through-one or moreinteriorcrosssections and also serves for the mutual adaptation of thevelocity distributions through one or more cross-sections traversedalternately in different directions or in neighboring interiorcross-sections traversed simultaneously by different media, for example,in crossing flow or in transverse flow.

Flow-influencing means which act according to a streamline principle arefor example: flow-influencing stream-lined shaping of the inner channelwalls at bends and enlargements in the flow path; roundings of theinterior, for example with radii of curvature which are about equal toor larger than the width of the channel section ahead of the roundedpart; gradual constrictions, for example in combustion chambers with thenarrowest point at about the level of the starting end of the flame, forexample the fuel gas outlet of the nozzle, and with gentle enlargementfollowing in the direction of flow. To provide for streamlined shapingof the channels,

arched brick construction as is conventionally used may be employed. Inone of the embodiments of the invention, the deflecting vanes may bearranged in a diagonal arrangement in the crest of the bend of a channelwith such a radius of curvature of the inner bend crest and such innerradii of curvature of the partialchannels defined on opposite sides ofthe vanes and between the walls of the brick-lined channels so that theradius of curvature is about equal to or greater than the inlet width ofthe partial channel. guide bodies or walls in two or more partialdiffusers may have a total enlargement angle of the partial diffuser upto degrees, and the guide surfaces of the vanes may be staggered inhead-sail fashion.

Flow-influencing means acting according to a resistance principle,according to the invention, are for example: stationary grids, multiplegrids, perforated plates, slotted plates and the like; closely spacedstraight grids with rounded, tapered, or blunt shape of the head;straight grids, angular or rounded grids preferably in diagonalarrangement; grids of equal inlet and outlet width of the grid channelswith close gn'd division; arched or rounded grids of unequal inlet andoutlet widths of the grid channels; movable grids; displaceable grids,multiple grids,

The division of a large enlargement by perforated plates, slotted platesand the like; slotted. or-

perforated sliding bricks with equal or unequal subdivision of breakssuch as slots or holes; grids fixed or displaceable as a unit withregulable passage cross-section, for example with shutter-like or'slidably arranged grid elements; grids with directing wall effect;subdivision of a big enlargement into partial diffusers with totalenlargement angle of the individual diffuser above 10 degrees; anddeflecting walls.

Combined flow-influencing means according to the invention are, forexample: means connected in series in the direction of flow; meansaccording to the resistance principle as for example grids and guidesurfaces or walls; means according to the streamline principle withsubsequent means according to the resistance principle as for exampleguide surfaces and grids or as for example guide walls and grids;combinations of grids with grids lying in another plane and/ or withguide surfaces and/ or with arcs for example in and at the housing of aregulating valve; functional spatial coordination or combination ofmeans according to the streamline principle; guide bodies or guide wallswith or without breaks and with or without arching in spatialflow-functional coordination with guide surfaces, that is, preferablyguide surfaces staggered in head-sail fashion; combination of severalmeans according to the resistance principle; guide bodies or guide wallsin functional spatial coordination or combination with grids;combination of several means according to the streamline principle, e.g. parallel or series arrangement of several sets of guide surfacesstaggered in head-sail fashion or of a set of guide surfaces staggeredin head-sail fashion and of a set of defle blades or vice versa, etc.

31, for the purpose of substantially disturbance-free de- The drawingsdisclose examples of the foregoing means or individual elementsaccording to the invention.

Figures 1 and 2 show a deflection of the flow arriving according to thearrow 1 by 180 degrees, the flow channel 2 being formed by the outer andinner masonry 3 and 4. At the deflection point the inner masonry 4 has acircular rounding 5. In the inlet the channel width 6 is about equal tothe channel width 7 of the outlet, while the channel width 8 at thedeflection point is at least nine tenths (Fig. 1) and at most one and ahalf times (Fig. 2) the dimensions of the channel width 6 or 7. Withsuch proportions or ratios a sufficiently disturbance-free deflection isobtained in such a structural element, applicable to diversifiedequipment at different points and in diverse combinations especiallywhen the radius of curvature of the rounding 5 is about equal to thechannel width 7. Moreover, recuperator channels may be arranged in theinner masonry 4, about perpendicular to the plane of the drawing.

Fig. 3 shows a deflection of degrees. The inflow according to arrow 9 isdeflected in the channel 12 formed by the inner and outer masonry 1t and11. The crest zone 13 slopes and the inside cross-section is subdividedat that point into two partial channels 15 and 16 by the provision of aguide body 14, such as a shaped brick. The flow body 14 can be variouslydesigned, but is preferably flat inside and arched outside. Thiselement, too, which is also suitable also for deflection angles otherthan 90 degrees, is applicable, like all of the elements later to beshown, in diverse equipment and combinations.

With it, flow detachments are not avoided completely but are muchsmaller than without such a guide body 14.

In Fig. 4 the deflection of the channel 19 formed by inner and outermasonry 17 and 18 is provided with rounded parts at the inside crest 20and at the outside crest 21. It is particularly suitable when the flow22 arrives with a velocity uniformly distributed over the cross-sectionof the inflow, for example according to the velocity distributiondiagram 23. The deflection point has installed in it a flow body 24, therounding of which adapts itself to the crest curvatures 20, 21 andpreferably lies closer to the inside crest 20. Such a flow body 24 maybe built up of individual arch bricks 25 or the like. In the directionof flow 22, the distance between the inside crest 20 and the flow body24, may advantageously decrease.

In a deflection according to Fig. 5, in which again inher and outermasonry 26 and 27 forms the channel 28, a deflection grid 32 is providedbetween the rounded inside crest 30 and the preferably rounded outsidecrest flection of the flow 29. For each partial channel the radius ofthe inside are should, for disturbance-free inflow 29, be about equal tothe inlet width of the partial channel. In the case of greatly disturbedinflow 29, however, this radius should be much greater than said channelwidth.

Fig. 6 shows for the inflowing flow 33, an abrupt enlargement of thecross-section according to surfaces 34 and 35 of the masonry. For theuniform spreading and possibly also for the deflection of the flow thereare provided here guide surfaces 36 of brickwork, staggered in head-sailfashion, in the zone of the crest of the walls 34, 35. Such a design maybe supplemented by mirrorsymmetry about the axes 37 or 38.

While for the elements according to Figs. 1 to 5 the flow development isindependent of the direction of flow, in Fig. 6 and various of thesubsequent figures, the flow development is more favorable in thedirection shown in the drawing than in the opposite direction, so thatin such arrangements for alternating direction of flow more care shouldbe taken in selecting the arrangement. Inpractice, however, examplesaccording to Fig. 6 and to be preferred for alternating direction offlow because these arrangementsare especially-effective in one directionand" because this 'direction of flow is then decisive for' 'the purposeof heat transmission.

In. Fig. 7 there is an abrupt unilateral "enlargement, formed by themasonry walls 39,40, of the inflow'crosssection. At the transition point41there is provided a set of guided surfaces 42 staggered in heads'aihfashion, and consisting of sheetmetal or cast metal. "Inthisa'rrangement the diffusor problem occurring'in flow'direction 43 and thenozzle problemoccurringimflow direction 44 are solved in such a waythat'n'o'essentialdis- 'turbances of the flow occur and alsoffor'exatn'pleinthe case of poorly distributed inflow 43, a 'goodtoi'un'iform velocitydistribution exists in'the enlarged cross-section. This arrangement canbe amplified by"r'nirror syrnirietry about the masonry to form asymmetrical element, naturally omitting this masonry'wall 40. In thecase of a non-uniform flow' pattern upstream'tosaidguiding "surfaces'thenon-uniformity is satisfactorilyelimin'ated even when'theguiding'surfaces ofthe vanes'are'loc'ated atan entrance of the diffuser.

The unsymmetrical abrupt enlargement of theflow cross-section formed inFig. 8 bythe masonry 45 and 46 is controlled by the arrangement of twosets of guide surfaces 47, 48 staggered in head-sail fashion, whichsolve thedifluser problemfor flow direction 49 and also stillsu'fliciently satisfactorily the nozzle problem "forcounterflowdirection 50. If such a'difluser'is highly-asymmetrical, more partialguide. surfaces are advantageously selected on the side of the biggerenlargement than on the side of the smaller enlargement. Thearrangement-according toFig. 8 may also be'sym'metri'cal, basing it'on'the uppe'r or on the lower half of the illustration.

Fig. 9 shows a main conduit51 with a lateral inflow cross-section 52 andan additional lateralinflow crosssection 53. For the proper introductionof the "flow-54 there is provided, at the inflow cross-section 52, a setof guide surfaces 55 in spatially corresponding arrangement andstaggered in head-sail fashion and which'set protrudes for example intothe inside cross-section 56 of the conduit 51. In addition, adisplaceable throttle grid 57 may be arranged in the inflow crosss'ection. In the inflow cross-section 53 of'the conduit 58 attachedlaterally or perpendicularly, a set of guidesurfacesi6 0 staggered inhead-sail fashion is arranged, for 'the .p'roper introduction of theinflow 59, in'suchawaytha't itdoes not protrude into the insidecross-section "56, for only immaterially so. This arrangement gives adeflection and introduction of the flows 54, 59 into 'the'conduit 51disturbance-free'to a very large extent. "With counter- I flow 61 in theconduit 51, 'the guide surface set 60 does not disturb the flow 61 atall and-theguide surfaceset 55 causes little disturbance of flowand'loss oftpressure, but in an immaterial and therefore harmlessmeasure because no appreciable response acts upstreamly to the heatexchange zone so that the flowpattern is notaflected at that location.

Fig. 10 shows an inflow channel 63 formed. of masonry 62, theinsidecroSs-section of which enlarges to amuch larger insidecross-section 64, with deflection about at a rightangle. Such aconstruction renders the'flow, problem especially di'flicult, above allwhen -the inflow 65 arrives with irregularvelocity distribution asshownby "Way of example in diagram 66. This'problem is-solved control oftheinflow (arrows'in"solidlifies) 'occurs by means of a' guide plate73;whi'c'h mayberourid'eti at the bottom and which cooperates with a set74 of guide surfaces in spatial coordination and staggered inht=.':1id=sail fashion. 'The inflow cross-section 72 may, in "addition,have a displaceablethrottle grid 75. Such displacea'ble throttle gridsmay, if desired,'be resorted'to quite generally in the inventionforthe'regulation of the quantity of flow.

According toFigj 12' there exists a sudden large crosssectionenlargement, formed by the'masonry 7'6,-'for'the inflow 77. The controlof the flow is achieved by arranging on both'sides at the'end of theinflow channel, but in the enlarged zone, preferably in symmetricalarrangement, two sets of guide surfaces 79, 'staggered in'head-sailfashion. Between the sets there may be provided an arched, possiblya-perforated, slotted, or broken guide plate 81 or a corresponding guidebody. This arrangement, too, permits of counterflow 82"and it alsopermits a very irregularly distributed inflow 77.

The examples describedso far relate to means and elements which operateessentially on the streamline principle. Figs. 13 to 20 show means andelements which control the flow essentially according to the resistanceprinciple. Some of the above and the following means and elements orarrangements and applications cam-however, be combined with one anotheras desired and'to .goodpurpose, it being unnecessary to showsuchcombinations for all needsoccurring in the practice, which areextremely varied and numerous depending on the model and nature of theequipment but if the elements are "properly employed and arranged, itwill always be possible to improve or to perfect the flow conditions.

In Fig. 13 is shown an inflow and outflow withequal cross-section, agrid brick arrangement, consisting of individual flat bricks 38 whichleave open partial channels 89, arranged for the flow 83 in the diagonalline through the crest between the sloping inside crest 84 oft-he'in'side masonry 85 and the outwardlysloping outside crest 86 of theoutside masonry 8 7. There may be used rounded flow approaching edges9d, pointed'and externally gently rounded flow approaching edges 91, as'well'as blunt flow approaching edges 92.

According to Fig. 14, the chamber formed by the masonry 93 is divided bya partition 94in such a way that thereresults a deflection of the'flow 95'by 180 degrees. In the diagonals between end 9,6of the'pa'rtition94'andthe1possibly also rounded or outwardly sloping corners97; 98of'the deflection space 99 there are, provided as flow-guiding means,cross-wise or at right angles tothe arriving flow, flat bricks 100, 101having blunt, rounded, or pointed and rounded endfaces.

"In'Fig. 15 there are, adjacent tothe deflection space 103, and formedby the masonry 102 bricklayed inflow channels 104 and outflow channels105 thereabove'arrangedparallel therewith. Here the sum ofthe insidecross-sections of the inflow channels'lM is often smaller than the sumof the inside cross-sections of the outflow channels 105. Sucharrangements with a partitionsuch as106 are frequently found inregenerative and recuperative equipment in refractory construction. Thedeflection space 103 contains, again in diagonal arrangement, deflectingblades 107 and 108, which may have an angular or'rounded shape. By suchan arrangement the inflow 109 and counterflow 110 are controlledsufiiciehtlydisturbance-free. This satisfies the'prerequisite of a'uniform charging (admission) or flow throughthe' channels 194,-105inboth directions of flow 109, 110.

-In the model according to Fig. 16 the design cor-responds to a largeextent to that shown in Fig. 15. Since here onlyone permanent directionof flow -109.is provided, it suflices to have one grid 111 of closespacing arranged diagonally in the upper portion of the deflectionchamber 103.

Figs. 17 to 20 show regulations of the inflow crosssection frequentlyoccurring in a regenerative and -recuperative plants, with means forfavorably aflecting'this regulation of the quantity of inflow. Air, forexample, is to be introduced from a channel 112 in direction 113 intothe channel 115 bounded by the masonry 114. For this purpose there arearranged, at the entrance of the duct 115, a slidable grid as indicatedby the double a1- row 117 and in front thereof a full brick or fullsheet 118, movable as indicated by the double arrow 119. According toFig. 18, the grid is designed as a sliding brick 120 which is providedwith slots 121 according to Fig. 19 or with holes 122 or the likeaccording to Fig. 20; the size, shape, distribution, and spacing ofthese slots 121 or holes 122 may vary.

Obviously there exist different possibilities of application of themeans and elements according to the invention as will be set forthhereinafter.

In Fig. 21 two inflows 123 and 124 are to be distributed over thechannels 125 of the brick lining 126 or the like, and in such a way thatas far as possible all channels carry an approximately equally largeflow. Such arrangements are found in recuperative and regenerativeplants, the inflow cross-section being subdivided by an angularly bentpartition 127 into two channels 128, 129 in such a way thatapproximately half the number of channels 125 are open to the inflow 123and the inflow 124. In practice several partitions 127 may be used. Themasonry has a step 130. For the proper distribution of the flow thereare arranged below the brick lining 126, which may also consist of gridbricks, several sets of guide surfaces 131, 132, 133 staggered inhead-sail fashion in the channel 128, and in like manner, in therecessed and higher-positioned portion 134 of the channel 129, similarguide surface sets 135, 136. For the double deflection 137 there isagain provided, between the crest 138 of the partition 127 and theequally high, upper edge of the step 130, a guide surface set 139effecting the disturbance-free deflection of the flow 124 and preferablyconsisting of guide surfaces staggered in head-sail fashion.

In Fig. 22, a flow 141 arriving through a channel 140 is to beuniformly, or more or less uniformly, divided over a plurality ofvertical channels 125 of the brick lining 126. The masonry 142 boundingthe channel 140 at the bottom ascends toward its end, and in thischannel 140 guide surface sets 143, 144, 145, 146 are arranged atintervals. On the horizontal line between the upper edges of these guidesurface sets, and below the channels 125, there may be arrangedadditionally throttle grids or the like. The throttle grid elements mayhave for example a rectangular section 147, U-section 148, angularsection 149, flat section 150 (bar grids, perforated plates), curvedsection 151, or an angular section 152 open for example toward theinflow direction. According to Fig. 23, the inflow 153 consisting, say,of fuel gas or burning or burned gas, is to flow through .a'brick liningwhich consists for example of brick billets 154 arranged in stage-likecriss-cross superposition with passage interstices. The masonry 155again forms a big and abrupt enlargement of the inside cross-section,the diffuser problem occurring in flow direction 153 being solved by thearrangement of a shaped brick 156 with or without spacing from thelowest course of the brick billets 154 in the diffuser 157. Thecounter-current 158 is heated air.

In Fig. 24, the masonry 159 forms a very strong diffuserlike enlargementof the inside cross-section. This is concerned with a recuperativeprocess in which the hollow bodies arranged in superposition in theenlarged portion, such as hollow bricks 160, house channels 161traversed crosswise to the plane of the drawing, with heat transmissionthrough the walls of the hollow bricks 160. The inflow 162 isdistributed favorably over the vertical channels 164 located between thehollow bricks 161) by the guide surfaces 163 arranged at the beginningof the difsail fashion.

lfuser, arranged as shown for example in staggered head- According toFig. 25, inflows 165 or 166 are to be distributed over channels 167 withmultiple deflection; these chnnels 167 may be, for example, inlet meansto combustion chambers of coke ovens. In this case a large chamber 169serving as a regenerating chamber is located alongside the brick lining168 and the channels 167, which chamber is partly partitioned bypartitions 170, 171. The lining 168 and channels extend vertically butall start in a common horizontal plane. The inflow 165 or 166 openingperpendicularly into the inlet conduit 172 may be deflected in a mannernot shown, by guide plates or the like. Throttle grids 173 may bearranged in the inflow channel 172, there being adjacent to the inflowchannel 172 a big enlargement 174 which at the inflow forms a diffuserand which, for proper distribution possesses either guide surfaces notshown or, as shown, guide plates 175 or walls in such number, length andarrangement that the enlargement 174 is divided into several individualdiffusers 176 of smaller enlargement angle. In case of counterflow 177,of course, these diffusers form nozzles. For further uniformity of flowthere may be arranged behind these guide plates 175, a throttle grid 178which also has a directing wall effect and which consists of flat bricksor flat plates with many parallel, preferably narrow partial channels.The inside cross-section behind the throttle grid 178 is lined withlining bricks and forms a partial regenerator 179. Subsequently the flowis deflected by 90 degrees and once more by 90 degrees, the insidecross-section of the first regenerator section 179 widening to theinside crosssection of the regenerator section 179 lying between thepartitions 170 and 171. To control this flow, known guide walls 180 arenot sufficient despite the proposals for improvement in the inlet.Additional means according to the invention in the form of deflectingwalls 181 are necessary. Appropriately also the second generator section179, which lies between the partitions 170 and 171, is additionallyequipped at its two ends with such deflecting walls 181. At thepartition 171, an end slope 183 may be built up of masonry or otherwiseproduced. The partial channels 183 and 184 resulting from the guidewalls 180 can be given an outwardly increasing width. As compared withthe usual system, there are thus obtained much more effectiveregenerators 179 or respectively much smaller dimensions and at the sametime a uniform distribution of the total flow over the channels 167,this leading also to a uniform flow through the subsequent combustionchambers for example of coke ovens and thus ultimately also to a stillmore uniform coke quality over the entire length of the coke chamber aswell as resulting in smaller losses or smaller inputs per unit weight ofthe coke produced.

Fig. 25 shows the device 185 in a simplified schematic manner. Device185 is presented in more detail in Figs. 26-29 and is shown in part inFig. 9. The device 185 controls the incoming gas 166, the incoming air16S and the outgoing gas 177.

In Fig. 26, a distribution chamber 186 is arranged below a standingregenerator or recuperator 187 or the like, and a regulating device withhousing 185, which in thiscase need not necessarily be provided withguide surfaces or the like, being located in front of the distributionchamber 186. The air inlet opening 188 has, in this illustratedembodiment, a displaceable, for example shutter-like throttle grid 189,and is also controlled by the air damper 190. Opposite the air inflow191 there is introduced through the conduit 193 a weak gas or other gasflow 192, while in the front portion of the housing 183 there isarranged the outflow valve 194 for the flow 1 95 going out in theopposite direction or leading to the outflow conduit 197 thereof. Thedistribution chamber 186 is designed so that it distributes well even arelatively unarranged inflow 191, 192 over all inside cross-sections ofthe regenerator 187 or the like. The partitions 198, 199 in thedistribution chamber 186 include two sets of slotted vanes 200- and 203in stepped formationbelow regenerator 187. See the. modification andloceition'in 'Figs. '21 and 22. Partitions 198 and 199 form a sharpelbow and an'abruptly widened diffuser so that, in the case of incomingflow 191, 192, a sharply enlarged diffuser of constant channel width isprovided perpendicularly to the plane of the drawing up to theregenerator .187. It is advantageous, depending on the passages totheregenerator 187, to reduce this width in the direction of theregenerator for the purpose of as extensive as possible a reduction ofthe enlargement visible in the plane of .the drawing. The steppedformation provided by vanes200and'293 acts satisfactorily also when theupstream flow contains a highly irregular flowpattern. For this reasonno particular features are needed to guide incoming air'191 and incominggas 192 and both are readily mixed due to arising eddies. 3 However, theeddies are unfortunately caused at an undesirable location, namely mostat the inner corner of inlet I93 resulting in an efiect that thequantities of air and weak gas which are required as maxima may not'bedelivered, or may not get the favorable composition with regard tocombustion. If the rate of air would be too little the manhole 196 maybe used as inlet of secondary air flow, too.

In case of reverse flow 195 coming'from the regenerator during. theheating period-this assembly of items 198, 199, 200 and203 acts alsosatisfactorily, but causes a larger drop of pressure. Actually designsof different loss of pressure are desired when said apparatus areoperated inbatteries of single unitsused in parallel.

.Partitions198and 199 may be built of metal, partition 199.rnaybealternately shaped. by the upper surface ofbricksarranged in .order todiminish the .flowcross sectionof'the rearend of chamber 186 opposite tothe entrance 'of flow through device .185. The end of the partition 198,formed for example of a bent sheetmetal wall, possesses in spatialcoordination a set 200 of guide surfaces staggered in head-sailfashion,whileat the are 201 of the partition 199 of brick or of sheetrnetal,which is made to extend to the bottom 202 of the masonry and which mayin part be curved, there is arranged preferably an additionalflow-regulating and flow-diffusing guide surface set 203.

In Figs. 27 to 30 are shown variants of the regulation of the inflow andoutflow as necessary in arrangements according to Figs. 25 and 26 andfor example in furnaces such as coke ovens.

To the masonry 204, which forms a big enlargement of the insidecross-section, there is adjacent, according to Fig. 27, the housing 185of the regulating organ, with packing by means of packing rings 205 orthe like. The housing presents a movable damper 207 for the flow ofincoming air 208. For aiding uniformity of the flow in adjusting therequired quantity of air, the inlet crosssection is here provided with adisplaceable throttle grid 209. The inlet cross-section which, in caseweak gas 211 is to be used instead of air, is located diametricallyopposite, possesses a set of guide surfaces 212 staggered in head-sailfashion, for deflection. In case of inflow 208 or 211, the outlet valve214 movable in the direction of the double arrow 213 is closed. Ifoutflow 215 is to be achieved, then, with the damper 207 closed and atthe inlet 210 closed at a point not visible, the outflow valve 214 ismore or less raised; its stiffening plate 216 possesses guide surfaces,such as a set of guide surfaces 217 staggered in head-sail fashion,which effect a deflection of the outflow 215 previously alreadyinfluenced by the guide surfaces 218, to a large extentdisturbance-free.

In Fig. 28, the position of the valves and dampers is selected somewhatdifferently, there being arranged for the air inlet damper 219 a guidesurface set 220 which is located somewhat inside the housing 185 butwithout substantially disturbing the counterflow 221 and if desired aregulatable throttle grid 234 is again additionally provided. Throughthis measure-at variance with the usual .237, this being sufficient forsome conditions.

throttling bynteans of a full..plate-the incomingaflow 222is'irifluenced particularly Yfavo'r'ably. The;.gas flow 224 or the likearriving from conduit- 233 is favorably deflected and distributed by,guide surfaces 225 which are arranged in the interior of'theinletconduit and which do not protrude into the interior of thehous'ing185 and here apply without gap against the conduit 223. Theoutflow valve 214 is here shown open. It may also have flow-regulatingmeans (not shown). In this variant, however, this merely reduces thedraft requirement. Hence it is thus possible, particularly if this-isappropriately done within a draft course at several individual-points tomake more powerful for example, especiallythe valves farther removedfrom the smoke stack, say according to the rule that the valveresistance is reduced the farther the valve is removed from the smokestack, so that all valves or regulating organs of a complete plant ,passabout an equally largeamount of air.

According to Fig. 29, the favorable deflection of the air inflow 226 isachieved in that at the inlet cross-section 227, which can be regulatedand closed by the movable damper228, there is arranged a likewiseregulable throttle grid 229 which is followed, in accordance with thedeflection desired, by a gentle rounding 230 of the housing 185 at thispoint. Also for the gas inflow 231 or the like a gentle rounding 232 isprovided. This rounding has the advantage of an inside space,substantially free from insertions, of the housing 185 and hence of anundisturbed outflow 233, which is controlled by the outflow valve 214.

The embodiment according to Fig. 30 shows an air damper 219 withthrottle grid 234 in the cross-section of the air inflow 235. Herethegas inflow 236 has no special flow-regulating means; ratherfits flowregulation is here achieved according to the resistance principle by asimple, or better a double-or multiple throttle. grid The outflow valve'2l4 for the regulation of the outflow 206 corresponds to that of Figs.28 and 29. In all these housings 185 of Figs. 26 to30, there is.provided in known manner a removable front plate 196-for the purpose ofrepair, cleaning, control, etc. In the valve models according to Figs.26 to 30, which are suitable for regenerators, recuperators, and otherequipment, the housings 185 may be selected smaller than previously, astheir inside cross-sections are better utilized with better distributionover the regenerators and the like. This affords the operative advantagethat a less intensive heat radiation takes place.

In Fig. 31, for example, a hot air flow 239 arriving through the inlet238 and coal-distillation gas flow 241 arriving from the inlet 240 cometogether diametrically under deflection by degrees in the stronglyenlarged cross-section 242 for the purpose of joint combustion, as isoften the case in muflle furnaces for the production of enamel ware andthe like, that is, for the heating of the muffle from the outside. Themasonry 243 subsequently forms a deflection space 244 where the flow isdeflected by degrees. Such deflections repeat several times. In Fig. 31,only one more rectangular deflection 245 is shown diagrammatically,these deflections being bounded by a partition 246 provided with a sharpbend 249 and by a straight partition 247. In the deflection space 244there is provided a set of guide surfaces 248 staggered in head-sailfashion, while in the deflection space 245 there is arranged, forexample di agonally, a deflection grid 250 or the like. In this way thisdifficult flow can be controlled. Additionally a small partial flow maybe guided from the deflection space 244, through an opening 251 possiblyprovided in the wall 247 at the top, to the subsequent chambers notshown. In the example of Fig. 31 there are preferably shown meansoperating on the streamline principle; they disturb the flame expansionmuch less than the means may according to the resistance principletheoretically likewise applicable according to the invention.

Figs. 32 and 33 show the application of means of the invention incombustion chambers or respectively burners in refractory construction.

The combustion chamber 253, bounded in Fig. 32 by the masonry 252,contains a nozzle 254 on a masonry channel 255. In the space 256 betweenthe masonry channel 255 or the like and the outside wall 252 there arearranged flat shaped bricks 257, for example set on edge, which leavefree partial channels 258, so that a favorable de-eddying of the airinflow 260 arriving through the channels 259 takes place. The result ofsuch an arrangement is a combustion of the gas flowing out through thenozzle 254 with a longer flame. The shaped bricks 257 with the functionof guide surfaces may be of difierent heights or staggered.

According to Fig. 33, the outside wall 263 of the combustion chamber 253is provided in the combustion zone with constrictions or the like 264,265, with the narrowest point preferably at the level of the nozzle 254.This, too, gives a good conveyance of the current of air 260 to the gas261 to be burned and an orderly, long-flame combustion, as is usuallydesired. The counter flow 262 is indicated for the sake of making itcomplete.

It is obvious that modifications and combinations not specifically shownand described can be utilized within the theory of the teachings of thepresent invention without departing from the scope thereof as defined inthe appended claim.

I claim:

A heat exchanger for coke furnaces, mufile furnaces, enameling furnacesand the like having refractory or brick-lined channels for theregenerative or recuperative heating of air by the combustion gases fromthe furnaces, said channels being bent at an angle varying from about aright angle to about 180 degrees and in which channels the air and gasesare subjected to changes in direction,

channels, thereby forming a substantially uniform cross sectional flowpattern, said deflecting means comprising a staggered series of curvedvane guiding surfaces positioned in its channel to provide a suctionside relative to the air and gases in the channel, the curved vanesbeing each disposed on the suction side of the subsequent vane, theresultant curvature of the series being greater than the curvature ofany single vane, the said resultant curvature of the series beingdefined by the curve which passes through the intersections of thechords of the vanes, the amount of the overlap of the vanes with respectto each other being sufficient to produce a jet velocity vector of thegases flowing in the channel in a direction substantially tangential tosaid resultant cur vature of the series, and the angle of attack of theincident gases in said channel to the first several vanes at one end ofsaid series being negative with respect to the direction of the velocityvector of the incident gas stream, whereby static and eddied zones ofgas flow in the bends of said channels are substantially eliminated bysaid defleeting means.

UNITED STATES PATENTS References Cited in the file of this patent335,558 Bissell Feb. 9, 1886 1,141,108 Diehl June 1, 1915 1,590,373Holbeck June 29, 1926 1,676,070 Bluemel July 3, 1928 1,944,074 ForterJan. 16, 1934 2,097,255 Saha Oct. 26, 1937 2,097,544 Ames Nov. 2, 19372,177,887 Huet Oct. 31, 1939 2,216,046 Peck Sept. 24, 1940 2,376,331Abrams May 22, 1945 2,554,092 De Poray May 22, 1951 2,592,899 HopkinsApr. 15, 1952 2,618,925 Wislicenus Nov. 25, 1952 FOREIGN PATENTS 819,028France Oct. 8, 1937

